Formatting issue with form-horizontal class on form.

I am using form-horizontal class on my form, and when I need to use 
this markup or else the form field spacing would be off.
<code><div class="control-group input-append ">
     <label class="control-label required" for="field">Field</label>
     <div class="controls date">
          <input type="text" id="field" name="field" value="" data-format="MM/dd/yyyy HH:mm:ss PP"></input>
          <span class="add-on"> <i data-time-icon="icon-time" data-date-icon="icon-calendar"></i></span>
     </div>
</div></code>
Unfortunately, this broke the datetimepicker plugin. I fixed the code on line 50
to look not only at current element, but parent element for input-append or input-prepend.